The present invention deals with and is directed to an automatic chemical feed system intended for feeding chemicals into the fluid of a fluid circulating system whether it is of the closed or open type, for the purpose of treating and removing contaminants which enter into a fluid in a fluid circulating system.
It is well known that in a typical circulation system, wherein a fluid such as water is circulated either incident to an air conditioning system, or for other reasons such as a heating system or the like, the liquid such as water, which flows through the system usually becomes contaminated with a variety of contaminants. This is especially true in the types of systems which have open tank reservoirs which are typically placed on the roof of a building. The contaminants may include contaminants in the air, which could include a variety of minerals or metals as well as microbial contaminants which are airborne. Contaminants also include scaling compounds which emanate from the piping system of the circulating system, and where the scaling can build up within the system and ultimately cause damage to the metal portions of the system. It is therefore important that virtually all systems have some type of chemicals which are fed into the system for the purpose of removing the most common contaminants incident to that particular system.
In the typical installation, the purification chemicals are usually brought onto the site in drums or kegs of some type, and are physically fed into the fluid reservoir on a timed basis. Often times, this is done manually, and in some instances, it can be done by a pumping system. For example, when the purification chemicals are in a liquid form, pumping systems are developed for pumping the liquid purification chemicals into the reservoir in a certain concentration in order to treat the fluid. The prior art has concerned itself with automating such types of systems wherein timing devices are used for the timed disbursement of liquid purification chemicals into the system.
In terms of the prior art, and for example, U.S. Pat. No. 3,163,174 shows a system which adds extra plumbing in order to bleed off water from the liquid circulating system, and treats the make up water which is added to the system as water evaporates. In this instance, the make-up water creates a vacuum to pull chemicals out of a separate tank and into the liquid tower. In this manner, the chemicals which are provided in a separate tank of purification chemicals are methodically placed into the system.
Another prior art U.S. Pat. No. 5,101,851 shows a system designed particularly for the removal of minerals from the water in the tank. In this instance, the patentee teaches a system which cycles on at a predetermined time which is determined by measuring the density or conductivity of the water in the system. The system will cycle on a solenoid to bleed water out of the system and carry out the contaminants. Indeed, the particular system disclosed in the aforesaid patent does not add chemicals to the system, but rather, bleeds off contaminated water and permits fresh make-up water to enter the system. The bleeding off occurs if the water reaches a certain level which would indicate that the water in the system has picked up a certain percentage of minerals and therefore needs to be removed with fresh water added.
It will be noted that the system disclosed therein uses a series of pumps and chemical drums and puts chemicals in the make-up water. In effect, the system disclosed the aforementioned patent is a density meter.
U.S. Pat. No. 3,915,187 shows another type of feed system which depends upon a venturi principal. It will be noted that in order to employ the system disclosed in the —187 patent, there is a requirement that the existing plumbing of the tower be changed in order to install this system. A float is provided which when it calls for water, permits make-up water to enter into the system and creates a vacuum. The vacuum then sucks chemicals into the water line thereby purifying the water. It should be noted that the purification chemicals which must be used in the system require that they be in liquid form in order for the system to operate as disclosed.
The present invention is intended to provide an automatic feed system which is retro-fittable to any existing circulating system without the need for changing the plumbing or electrical systems which are in place relative to such systems. Further, the present system uses purification chemicals which are in a solid particulate format rendering the use of such chemicals convenient and easier to use thereby avoiding the need to haul and position multiple gallon drums of chemicals into a use position.